Federal and state governments have imposed increasingly strict regulations over the years governing the levels of hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxide (NOx) pollutants that a motor vehicle may emit to the atmosphere.
In diesel engine systems, a diesel particulate filter (DPF) is provided to trap the particulate matter in the exhaust passage of the diesel engine. Conventionally, a dosing valve is mounted into the exhaust passage of a diesel system to inject diesel fuel into the exhaust stream to reduce the particulate matter and thus reduce NOx emissions. Since the temperature of the exhaust passage near the manifold can reach 600 C, cooling is desired to ensure that the valve survives.
Thus, there is a need to provide a cost-effective, exhaust dosing valve that can be cooled.